The present invention relates to a thermoplastic resin composition containing zinc oxide whiskers. More particularly, it relates to a novel styrene resin composition improved in mechanical strength (especially flexural modulus), heat resistance and vibration damping characteristics without damaging the ease of molding and excellent surface appearance of a molded article which are inherent to styrene resins, and materials suitable for exterior materials of business and office machines and light electrical appliances are provided.
Hitherto, improvement of properties of thermoplastic resin compositions has been carried out by incorporating one or more of glass fiber, powders such as talc and calcium carbonate, flaky materials such as mica and whiskers such as potassium titanate into the composition.
It has been known that use of inorganic fibers such as glass fiber which have a high aspect ratio is effective especially for providing resin composition excellent in mechanical strength.
However, though mechanical strength can be improved by use of inorganic fillers such as glass fiber, the surface state of molded articles is considerably deteriorated.
On the other hand, when inorganic fillers such as glass fiber which has a low aspect ratio are used, the surface state of molded articles is improved, but there is little improvement in mechanical strength. In addition, even if mechanical strength is improved by adding these inorganic fillers, loss factor (.eta.) obtained by measuring viscoelasticity tends to decrease and hence the vibration damping characteristics thereof are not preferred for use of the composition as housings of business and office machines or light electrical appliances.
Thus, development of resin composition superior in mechanical strength, surface state and vibration damping characteristics of molded articles has been demanded.